Kevin Appier was pitching against the toughest opponent of his career. It was 1998 and Appier’s season had been ruined by surgery on his right shoulder. His arm was his foe.

When he came back to make three appearances at the end of the year, Glendon Rusch, his Royal teammate, noticed Appier didn’t have his previous precision.

But Rusch came away even more impressed with Appier on a mound.

“He really didn’t have nearly his normal stuff, but he was still out there battling his way through every inning and still getting guys out,” Rusch said yesterday. “A lot of guys find it hard to pitch in that situation.”

Rusch watched Appier with the A’s last season and he still saw the intensity, but he also saw something else from Appier.

“I think definitely when I saw him last year on TV, he is all the way back,” said Rusch of Appier, who officially became a Met yesterday. “He looked as healthy as ever.”

The Mets hope Appier can pick up the same 15 wins he recorded in Oakland last regular season to fill the victory void left by Mike Hampton’s departure.

Interestingly, Rusch describes Appier’s personality to be much like Hampton’s.

“He definitely keeps more to himself,” Rusch said.

“He’s not the type of guy who will come out and do a lot of talking to the younger guys. He kind of does his thing and keeps to himself and he is similar to Hampton in that way.”

Rusch doesn’t think Appier will have any problems adjusting to New York despite his small-town roots.